The objective of this research was to analyze the Peruvian regulatory framework regarding the regulation and control of mining activity related to environmental impact. The present work was based on descriptive research of bibliographic review to obtain relevant information related to the publication of environmental laws, the creation of organisms and control instruments and the impact that the laws have. against the supervisory function of these bodies. It was concluded that in the course of the year from 1997 to 2014, a total of 15 environmental laws were formulated, in addition to compliance with these, bodies such as the OEFA, MINEM, MINAM, SEIA, ECA and LMP were created, who are in charge of supervising and control mining activities and impose sanctions depending on the severity, likewise in 2013 legislative decree 054-2003 was enacted that weakens the aforementioned bodies in order to promote mining investment.
The objective of this research was to analyze scenarios through decision making and risk analysis, which was applied in the construction of a cruise ship in the Atlantis project. The methodology that was used is quantitative based on event information, which through a graphical representation facilitated the understanding and interpretation of the decision tree, in addition, statistical methods were applied for risk analysis, it should be noted that in order to obtain data was considered that of other studies. The results obtained from the decision tree were that the first alternative that was proposed had a NPV of $3,970, the second of $3,405 and regarding the risk analysis, the coefficient of variation of the first option is 57% and the second 60%. Therefore, after having made the graphical representation and verified the risk, it is concluded that, for the construction of the cruiser, option 1 has the most viable decision regarding the path traced in the graph, the highest NPV and the lowest risk.
In the present investigation, leather waste from the footwear manufacturing industry was used to make polymer-bound compounds. The objective of this work was to find the most appropriate leather and polymer mixtures that achieve the best physical-mechanical properties for possible use in applications in the leather-footwear sector. For this purpose, the effect of the type of binder polymer (polyester resin (RP), polyurethane (PU) and urea-formaldehyde (UF)) and the polymer/leather mass ratio (70/30; 80/20 and 90/10) on tensile strength, linear shrinkage and absorption were studied. In addition, the influence of the average leather particle size (0.840mm; 2mm and 4.76mm) and the leather/PU volume ratio (70/30, 80/20 and 90/10) on the tensile strength were studied. For the process of elaboration of study specimens with constant thickness, the manual hydraulic pressing method was used using an open steel mold and 8 tons of force. From the results obtained in the agglomerates with different polymers, it was determined that the PU allows obtaining the highest values of tensile strength, achieving a value of 9.5 MPa at a vol. ratio of 90/10 PU/leather. While the 70/30 UF/leather mix achieved the lowest tensile strength with a value of 1.7 MPa.Regarding moisture absorption, the highest value of 129% was obtained for the 70/30 UF/leather combination, while the minimum absorption of 5% was presented in the 90/10 PU/leather compound. For linear contraction, the lowest levels were obtained in the 70/30 PU/leather compound, while the highest values were identified in 90/10 RP/leather agglomerates.In the case of the agglomerated compounds of leather and PU, it was determined that for the 90/10 leather/PU ratio, the tensile strength tends to increase as the particle size becomes smaller. However, for the 70/30 and 80/20 ratios, the behavior is inverse, but the highest mechanical tensile strength (6.02 MPa) was obtained in test tubes with 70/30 leather/PU and 4.76 mm particle size of recycled leather.
In this research, the process of gold and silver extraction from a refractory gold-silver sulfide ore, sourced from the Gran Chimú Province in the La Libertad department of Peru, was evaluated. The extraction was carried out in two stages, the first being called indirect bio-oxidation, and the second involving conventional cyanidation. In the first stage, an acidic solution from the area was used to cultivate Thiobacillus ferrooxidans bacteria, which was promoted by the addition of salts (9K). The objective of this stage was the transformation of ferrous cations to ferric, which was evidenced by the color change of the acidic water to red. In the second stage, a solution of sodium cyanide and calcium oxide (lime) was used, and the total cyanidation time was 51 hours at an average pH of 10.5 and ambient temperature. The quantification of gold and silver was done through a dry method (fire assay). The evaluated process variables were the concentration of silver salt (0, 0.75, and 1.5) mg/g, mineral particle size (80% passing 100 mesh, 80% passing 200 mesh, and 80% passing 325 mesh), and temperature of indirect bio-oxidation (25, 45, and 65)°C. To evaluate the effect of the bio-oxidation pretreatment, conventional cyanidation tests were conducted, resulting inextraction percentages of 44.61% for gold and 48.98% for silver, using 80% passing 325 mesh particle size. This indicated the need for the mentioned pretreatment to release the gold and silver from the ore. Meanwhile, the extraction percentages using the two stages were 61.44% for gold (80% passing 325 mesh, 65°C, 0.0 mg/g) and 94.24% for silver (80% passing 200 mesh, 65°C, 0.75 mg/g) in the best cases, and 35.98% for gold (80% passing 100 mesh, 45°C, 0.0 mg/g) and 41.44% for silver (80% passing 100 mesh, 25°C, 0.0 mg/g) as the lowest recorded values..
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